Steve Mirsky: Welcome back to part two of my conversation with Lee Billings, author of Five Billion Years of Solitude: The Search for Life Among the Stars.

We’re on the verge of being able to actually analyze the contents of the atmospheres of some of these rocky exoplanets, which could tell us not that they’re inhabited or that there’s a technological civilization, but it would be some strong circumstantial evidence that there is some kind of at least industrial processes going on.

Lee Billings: Yeah, that’s feasible. That’s feasible. I will say, though, that, you know, the best candidate for that that people like to talk about is chlorofluorocarbons, right, CFCs. Because again, we’re dealing with just our own little sample, and what we’ve experienced in the past.

Steve Mirsky: If the aliens are using hairspray we’re going to know.

Lee Billings: Well, I’d like to say so, but those signals are really, really weak, so anything that we can imagine, any kind of thing that we can countenance. I mean in theory, sure, you could have an entire civilization devoted to hairspray, right?

Steve Mirsky: Right.

Lee Billings: And then they’re just all – that’s their religion, they just spray this stuff into the air and that’s all they do, and every Sunday everyone does it en masse by the billions or trillions. That kind of scenario you could in theory see something building up that we could see with the instruments that we’re contemplating now, but something like what we did to our planet and what caused the ozone hole, that’s kind of off the table for us to see. But again, you know, not everything’s like us out there, right? And how similar things are going to be to us is a very big question, we don’t really know the answer to it. But we could see things like that.

We could certainly see things like oxygen or methane, and on our own planet those are the main things that sign post life. So if you think about looking at the Earth from another star, let’s say the star is 30 light years away or 50 light years away, you know, relatively close by in the big scheme of things, but that’s really far away, so you could see, you know, if you could manage to get a picture of our planet, isolate its light from the overwhelming glare of the star, this little pale blue dot, right? You could look in its atmosphere and you could get that atmospheric information from that light. You could see oxygen and you could see methane. And the fact that those things are coexisting together is let’s say thermodynamically implausible; that’s something that shouldn’t happen. If you put those two things, oxygen and methane, in a sealed box with, you know, room temperature and pressure, those are going to turn into carbon dioxide and water vapor; they aren’t going to stick around. So you see them both together, that means something is constantly replenishing them. obviously on our planet oxygen comes from, you know, things like cyanobacteria and green plants, and then the methane comes from these so-called methanogen single-celled organisms that are anaerobic, they don’t like oxygen, it kills them, and they live in like rice paddies and cow guts and stuff like that.

So one point to that is that if someone is looking at us, in theory they could be looking at our radio transmissions, they could be tuning into I Love Lucy and things like that, but that takes really, really, really big radio telescopes. Really big. Bigger than we have ever contemplated building. Bigger than we probably ever will build. I mean knock on wood, right? But who knows? Whereas, you know, something like oxygen, something like methane from the little pale blue dot, that’s something that we can contemplate doing right now. You know, we know how to build a telescope that will do that right now. So to me that says if someone’s watching us from far away, you know, they’re probably not tuning into I Love Lucy, they’re probably not listening to our TV and radio; they’re looking at our atmosphere and they’re saying, “Something’s ticking there. Let’s check it out more.” So the same way that the aliens could do that to us, we could do that to them.

Steve Mirsky: Right. Not to mention it significantly increases the time in which they’d have that data available to be looking at it. If there’s a civilization 300 light years away they’ll be able to see our atmosphere and know stuff that’s – what’s going on chemically. Whereas to see I Love Lucy they’ve got to be within the last 60 years.

Lee Billings:Yeah. And it’s pretty startling when you think about it how far – you know, if you think about the Sun and its light as kind of this ever-expanding shell, this bubble of light that is moving at the speed of light out from the center, you know, from the Sun and our solar system, obviously its edges are about 4.6 billion light years away. And really, you know, the first signs of life that we can find are about 3.5 billion years old; it was probably back there before then. The point is that you track where the signals of Earth being alive are in space. I’m not saying something that far away can detect them, but I mean in theory – in theory, you know, all that stuff has already washed over all the nearby galaxies, all the nearby galactic clusters and super-clusters, so that cosmic calling card, I guess, of our existence here, of life’s existence here on the planet, you know, you can’t put that back in the bag; that’s way out there. So anyone who’s really looking hard should know to some degree that we’re here.

Steve Mirsky: Mm-hmm. Matt Mountain is a great name. He’s one of the central characters in the book.

Lee Billings: Yeah, Matt Mountain is I have to say probably the most eloquent statesman for this grand quest that I try to lay out in the book, which is, again, you know, we shouldn’t just be finding these planets, we shouldn’t just be stamp collecting and saying, “Oh, there’s another planet. Oh, there’s another planet. Look at this book of planets we have and we have them by the thousands. Isn’t that cool?” It’s not about stamp collecting; it’s about going out and not just finding these things, not just detecting them, but actually studying them and figuring out what they’re like, what are their atmospheres like, what are their surfaces like, what are their climate like, do they have anything alive there.

The way we do that, the best way that we know how is to build a big space telescope. Matt Mountain is the director of the Space Telescope Science Institute. He’s extremely well-spoken, extremely eloquent, and he has been I think a tireless, careful advocate of this for quite some time. And he thinks that it’s a worthy mission for NASA, and it’s the kind of thing that can be a potent synergy for a space program. Because if you think about it, well there’s two sides to the space program; people like to pit them against each other; there’s kind of robotic exploration and big space telescopes, and there’s the human stuff, there’s the meat in tin cans, you know, let’s go to Mars, let’s go to an asteroid, to the Moon, whatever.

Well, you can have these things work in synergy, and we’ve seen this before with the space shuttle and the Hubble telescope. The reason why the Hubble telescope revolutionized so much of science and why it was such a huge success, despite as people, you know, my age and your age will remember, despite being a huge initial boondoggle at first; it had a flawed mirror, it wasn’t going to work, it was essentially written off. Well, the space shuttle can visit it again and again and service it. It serviced it five times over its life, each time, you know, this crack team of astronauts went out there, risked their lives, were basically doing like fine surgery wearing oven mitts and, you know, like a welder’s mask out in the vacuum of space. But they made this thing work, they made it a new telescope every single time essentially. And the point is is that you can have these synergies where we can build and service big space telescopes out there in space. This is a way to get over things like launch costs. It’s a way to engage the – I think the human side of NASA’s programs while they’re waiting around to go to Mars, while they’re waiting to go to an asteroid or the Moon or whatever, ‘cause that’s going to take time. In the meantime maybe we should get better at building big structures in space and servicing them. You know, you can do that with robots too, but this is something that Matt Mountain can actually talk about much more eloquently than I can. But that is one of his thrusts when he sees this. The whole point is that we need to get bigger and better space telescopes up there so that we can actually study these planets and figure out what they’re like.

Steve Mirsky: And Wesley Traub is another one of the cast of characters.

Lee Billings: That’s right. You’ve gone through the whole thing. So Wesley Traub is out of JPL, NASA’s Jet Propulsion Laboratory, which it runs along with Cal Tech, the California Institute of Technology. And he is, last I checked, the director of NASA’s exoplanet exploration programs. He’s kind of the one who oversees a lot of that. And he was really involved actually – when I spoke to him he was actually cleaning out his office. He had all this paperwork built up in his office; I can’t remember how many linear feet he had, but just boxes and boxes of paperwork, and he was cutting that down in half. So he was taking a lot of the literature that had accumulated over the past decade or two decades or so around this quest of building big space telescopes and he was kind of throwing that in the trash can. And the reason why he was doing that is because back in the mid-‘90s, actually right around the time that Geoff Marcy, the planet hunter that we mentioned earlier, made some of the first discoveries of exoplanets, NASA really got behind this and they said, “Hey, we’re going to build some of these big space telescopes.” They called them terrestrial planet finders, TPFs. And, “We’re going to build some of these things and we’re going to launch them” and Wes Traub got involved circa I think 2005. He had been involved earlier, but JPL hired him in 2005 to come lead this effort to make this happen.

Originally they were going to launch two of these things, two TPFs, one invisible light and one in infrared light, and we can go there about why they’re launching two instead of one. But the whole point is they were going to launch two. The first one was going to launch next year, Steve; it was going to launch in 2014. The infrared was going to launch – that was the optical. The infrared one was going to launch before 2020. Now you may notice we haven’t really heard much about that recently, and that’s because in 2006 they got canceled. So the year after he got there, after Wes Traub got to JPL to build these big space telescopes to the tune of $50 million a year, trying to figure out the best ways to do it, all the engineering studies, the rug kind of got pulled out from under him, and that was due to a lot of different things. Astronomers were bickering with each other about which designs would be best; they were bickering with other astronomers about whether or not exoplanets were important to invest all this money in.

A lot of folks, and I can see where they come from, a lot of astronomers are not really interested in planets; they’re interested in colliding galaxies and super massive black holes and all these things that don’t seem to have as much to do with life and with our existence here. And they were worried that all these big billion-dollar space telescopes for finding planets were going to essentially impoverish them and leave nothing for them to do. And that’s a legitimate concern.

There was also the constellation program, the effort to send astronauts back to the moon and build a moon base and things like that, that President George W. Bush encouraged and planned. All these things served to siphon money away from NASA’s astrophysics efforts and create a lot of instability, and the end result was that, yeah, in 2006 the TPFs were, I believe the term was “deferred indefinitely” officially, and they were sent to what I like to call the place where grand dreams go to die, which is NASA’s technology development programs, just kind of trickle fed and kept on life support via a little IV, but, you know, we’re not going to launch those things anytime soon it seems like.

So Wes Traub is a great guy, kind of I guess a tragic figure in a way, just because, you know, he, like everyone else in the book wants to make this happen, believes it’s going to happen in his lifetime. And we’re seeing these opportunities kind of slip away from us, because right now NASA’s saying, “Well, the soonest we’re going to even think about doing that is in the 2030s.”

Steve Mirsky: Mm. And you also talk about Sara Seager at MIT.

Lee Billings: Sara’s an interesting one, and very interesting character, yeah. Sara is a planetary scientist and astrophysicist; she kind of does both things. And she’s a full professor at MIT; she’s relatively young, in her 40s, early 40s. And to me she does kind of represent, I guess, you know, some hope for the future. She’s very interested in building these sorts of big space telescopes, these TPFs, these terrestrial planet finders. But increasingly she’s aware that NASA may not be the right way to do that; that if you want to hitch your wagon to the federally funded, you know, big standard paradigm way of doing science that we’ve been doing for the past half-century or so through things like NASA and the NSF, you know, you’re going to be waiting a very long time maybe to get results.

So she’s made some waves recently by trying to get more involved with the commercial space flight industry, trying to get more involved with things like cube sats, these very, very small satellites that can be launched very cheaply. And she’s really just trying to innovate and push the boundaries of, you know, what we can realistically expect to do in the next 10 or 20 years, maybe without NASA’s help. Maybe we can actually go out and find some of these life-bearing planets or potentially habitable planets out there. Maybe we can actually get those pale blue dots faster, better, and cheaper, right, without getting NASA involved. I don’t really know if that’s true, but it’s certainly something that’s developing right now and brewing, and I think it’s important to highlight that possibility.

Steve Mirsky: You’re going to have to update this book in another five, ten years.

Lee Billings: Well, maybe. You know, NASA does have some things in the works that I was really fortunate that a lot of these things kind of shook out right as the book went to press, so I was able to update some things. So for instance, NASA’s Kepler mission, which we mentioned earlier, which has found more than 3,500 planetary candidates, and there’s probably thousands more still waiting in its databases to be analyzed, that mission unfortunately essentially came to an end back in May of this year, when there was a spacecraft malfunction, it couldn’t really point itself properly anymore to survey for all these planets.

Steve Mirsky: It’s got a bum wheel.

Lee Billings: That’s right, it’s got a bum reaction wheel, so it can’t really point very well. Now they’re looking at ways to fix it and continue the mission. But the point is is that the glory days of Kepler are over; they’re in the past. But it has given us this great treasure trove of data. Within that data there probably are a few Earth-sized planets around Sun-like stars that are in year-long orbits. So it has, I think, achieved its primary mission. And the latest news out of the Kepler mission actually, it looks like about 1 in 5 Sun-like stars in the Kepler field anyway, in the little swath of the galaxy it’s looking at, but you can extrapolate that, but about 1 in 5 Sun-like stars seem to have an approximately Earth-mass planet in the habitable zone. So that’s huge. And that’s what we need to kind of spec out these big space telescopes in the future.

The next thing that NASA is planning to do is to launch a mission called TESS, the Transiting Exoplanet Survey Satellite. That’s supposed to go up in 2017 and that’s going to be looking at nearby stars, stars that are close to us for transiting planets. Kepler looked for transiting planets, but most of the stars that it looked at were thousands of light years away, so they’re not really good for follow-up study because they’re just too dim; you can’t get enough light from them. TESS will be looking at nearby stars, looking for transiting planets. And the purpose of that for the James Webb space telescope that’s supposed to launch in 2018. And Webb might be able to just maybe look for things like water vapor in some of these so-called super-Earth planets we’re finding that are quite probably rocky, but, you know, anywhere between two to five times the size of Earth, or two to five time the mass of Earth. We could look at some of those planets when they’re transiting around nearby stars and maybe see things like water vapor.

But it’s probably going to leave us at the cusp; it’s probably going to leave us right at the cusp of what we really want to know, which is, again, whether or not they harbor life, whether or not they’re really habitable in ways that we can appreciate whether or not they’re really Earth-like. And I think to do that, you know, we’re really going to have to take the next big step. Maybe there are some technological breakthroughs that no one can anticipate that are going to happen. But I am pretty confident actually that this is going to hold up – this book is going to hold up for at least the next decade. So we’ll see. Knock on wood again.

Steve Mirsky: What was the experience of writing the book like for you? Did you find yourself – obviously you had a huge interest in this field going in, so what happened to you as you wrote the book?

Lee Billings: That’s a really great question, Steve.

Steve Mirsky: Did you get sick of it? Obviously not.

Lee Billings: Well, you know, I’m definitely – I guess I’m at the point now where I’m like, “What else can I really write about this?” I’m kind of waiting for – at this point we’re waiting for the field to catch up. You know, there’s a lot of speculation and a lot of dreams in there, in the book about what we can do. Well, it’s time we actually started to go out and do it. And that’s one thing that I ended up feeling very strongly, was kind of a sense of sadness, I guess, and of squandered opportunity, and the notion that, you know, when we get back to what we started this conversation with, the notion of l, the notion of how long technological civilizations last on a planet like Earth, you know, you look around you you can see various trends, you can kind of put them all together and man, it’s kind of a grim picture.

You know, you see the world’s brightest minds, the most passionate people you can think about, the smartest people you can think about, and they’ve devoted their lives to this quest to figure out whether or not we’re alone, to find other Earth-like planets, to find out our prospects in this great big wondrous place we call the universe. And despite their best intentions, despite how smart they are, despite everything that they are doing right, they were stymied and stifled and it looks like now this opportunity is slowly slipping away from us, at least slipping beyond many of our lifetimes. So I was saddened by that, and I think that’s diagnostic and symptomatic of just the general problems we have as a society whenever we want to try to come together to do great things. I think that, you know, it doesn’t always work out, and I hope it works out in this case. But I had that sadness.

And then the other thing that really was also kind of sad, but also kind of happy, this bittersweet feeling was just talking to people like Mike Arthur, the geologist, talking to people like Jim Kasting, this expert on planetary habitability, and getting a sense of how old the Earth really is, like how long 4.6 billion years is in comparison to a human life. ‘Cause you can throw those numbers around, and to most people that’s just like, you know, an extra three zeroes on the end of a numeric string, but, you know, when you actually talk to people who appreciate the depth of time and all that’s happened in the past and how fleeting and ephemeral we are, and yet how special we are, how we are totally unprecedented in the history of the planet. You know, the cyanobacteria 2.5 billion years ago, they changed the planet like we’re doing, they caused a mass extinction, they polluted the environment and changed everything, but it was a whole class of organisms; it wasn’t just one species. We are really unique. We really are – I mean there’s some kind of anti-Copernican element here, you know, maybe we aren’t as mediocre and average as a lot of the physical sciences tell us. There’s been a trend throughout hundreds of years now of physical science inquiry, you know, physics and astronomy and what-have- you that says, “We’re not special. You’re not special. You don’t matter. You’re nothing.” And that I think in the big cosmological scheme of things you can make that argument. I don’t think in terms of our galaxy, in terms of our planet, in terms of our solar system you can make that argument anymore. I think there’s a very good case to be made that we actually might be very special. This might be the coolest thing going right now in the Milky Way galaxy, what’s going on on planet Earth. We don’t know. The point is is that we could find out soon if we put our minds to it.

Steve Mirsky: We’ll be back right after this word from the Nature Podcast.

Female: This week, how UV rays cause skin cancer to spread, using crystallography to probe the deep earth, and Einstein’s lost manuscript. Listen at Nature.com/nature/podcast.

Steve Mirsky: That’s it for this episode. Get your science news at our website, www.scientificamerican.com, where you can read the article Hundreds of New Exoplanets Validated by Kepler Telescope Team that was written by our space reporter Clara Moskowitz. And follow us on Twitter, where you’ll get a tweet whenever a new item hits the website. Our Twitter name is @SciAm. For Scientific American Science Talk I am Steve Mirsky. Thanks for clicking on us.

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